Conventional fluoroscopic registration artifacts have X-ray transparent bodies holding radio-opaque fiducials in predetermined and fixed positions on the registration artifact. The fiducials show up as distinct dots on an X-ray and used to coordinate and register to a common coordinate system multiple X-ray images of a patient taken from different perspectives. The registration artifact remains fixed in position from one image to the next in order to register the images, as an assumption is made that the fiducials in the respective images are in the same positions.
In certain situations, it is advantageous or necessary to relocate the registration artifact. For example, in some instances it is difficult to fit the registration artifact and the relevant anatomy within the fluoroscopic field in the fluoroscopic images due to the particular anatomy or physical configuration of the patient. An obese patient may present such challenges, for example.
One solution has been to track the position of fluoroscope in an operating room rather than use a registration artifact. However, tracking the fluoroscope requires expensive modifications to the fluoroscope.